From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.15.18]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3vCPnr21DvzDq99 for ; Tue, 31 Jan 2017 22:54:55 +1100 (AEDT) Message-ID: <1485863317.4498.2.camel@gmx.de> Subject: Re: [tip:sched/core] sched/core: Add debugging code to catch missing update_rq_clock() calls From: Mike Galbraith To: Sachin Sant , Matt Fleming , Michael Ellerman Cc: "linuxppc-dev@lists.ozlabs.org" , peterz@infradead.org, "linux-next@vger.kernel.org" , linux-kernel@vger.kernel.org Date: Tue, 31 Jan 2017 12:48:37 +0100 In-Reply-To: <33118425-8548-475A-8DED-9A2424C0BCCC@linux.vnet.ibm.com> References: <20160921133813.31976-8-matt@codeblueprint.co.uk> <87tw8gutp6.fsf@concordia.ellerman.id.au> <20170130213435.GM31613@codeblueprint.co.uk> <33118425-8548-475A-8DED-9A2424C0BCCC@linux.vnet.ibm.com> Content-Type: text/plain; charset="iso-8859-7" Mime-Version: 1.0 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 2017-01-31 at 16:30 +0530, Sachin Sant wrote: > Trimming the cc list. >=20 > > > I assume I should be worried? > >=20 > > Thanks for the report. No need to worry, the bug has existed for a > > while, this patch just turns on the warning ;-) > >=20 > > The following commit queued up in tip/sched/core should fix your > > issues (assuming you see the same callstack on all your powerpc > > machines): > >=20 > > https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?h=3Ds= ched/core&id=3D1b1d62254df0fe42a711eb71948f915918987790 >=20 > I still see this warning with today=A2s next running inside PowerVM LPAR > on a POWER8 box. The stack trace is different from what Michael had > reported. >=20 > Easiest way to recreate this is to Online/offline cpu=A2s. (Ditto tip.today, x86_64 + hotplug stress) [ 94.804196] ------------[ cut here ]------------ [ 94.804201] WARNING: CPU: 3 PID: 27 at kernel/sched/sched.h:804 set_next= _entity+0x81c/0x910 [ 94.804201] rq->clock_update_flags < RQCF_ACT_SKIP [ 94.804202] Modules linked in: ebtable_filter(E) ebtables(E) fuse(E) bri= dge(E) stp(E) llc(E) iscsi_ibft(E) iscsi_boot_sysfs(E) ip6t_REJECT(E) xt_tc= pudp(E) nf_conntrack_ipv6(E) nf_defrag_ipv6(E) ip6table_raw(E) ipt_REJECT(E= ) iptable_raw(E) iptable_filter(E) ip6table_mangle(E) nf_conntrack_netbios_= ns(E) nf_conntrack_broadcast(E) nf_conntrack_ipv4(E) nf_defrag_ipv4(E) ip_t= ables(E) xt_conntrack(E) nf_conntrack(E) ip6table_filter(E) ip6_tables(E) x= _tables(E) x86_pkg_temp_thermal(E) intel_powerclamp(E) coretemp(E) kvm_inte= l(E) kvm(E) irqbypass(E) crct10dif_pclmul(E) crc32_pclmul(E) nls_iso8859_1(= E) crc32c_intel(E) nls_cp437(E) snd_hda_codec_realtek(E) snd_hda_codec_hdmi= (E) snd_hda_codec_generic(E) nfsd(E) aesni_intel(E) snd_hda_intel(E) snd_hd= a_codec(E) snd_hwdep(E) aes_x86_64(E) snd_hda_core(E) crypto_simd(E) [ 94.804220] snd_pcm(E) auth_rpcgss(E) snd_timer(E) snd(E) iTCO_wdt(E) i= TCO_vendor_support(E) joydev(E) nfs_acl(E) lpc_ich(E) cryptd(E) lockd(E) in= tel_smartconnect(E) mfd_core(E) i2c_i801(E) battery(E) glue_helper(E) mei_m= e(E) shpchp(E) mei(E) soundcore(E) grace(E) fan(E) thermal(E) tpm_infineon(= E) pcspkr(E) sunrpc(E) efivarfs(E) sr_mod(E) cdrom(E) hid_logitech_hidpp(E)= hid_logitech_dj(E) uas(E) usb_storage(E) hid_generic(E) usbhid(E) nouveau(= E) wmi(E) i2c_algo_bit(E) drm_kms_helper(E) syscopyarea(E) sysfillrect(E) s= ysimgblt(E) fb_sys_fops(E) ahci(E) xhci_pci(E) ehci_pci(E) ttm(E) libahci(E= ) xhci_hcd(E) ehci_hcd(E) r8169(E) mii(E) libata(E) drm(E) usbcore(E) fjes(= E) video(E) button(E) af_packet(E) sd_mod(E) vfat(E) fat(E) ext4(E) crc16(E= ) jbd2(E) mbcache(E) dm_mod(E) loop(E) sg(E) scsi_mod(E) autofs4(E) [ 94.804246] CPU: 3 PID: 27 Comm: migration/3 Tainted: G E 4= .10.0-tip #15 [ 94.804247] Hardware name: MEDION MS-7848/MS-7848, BIOS M7848W08.20C 09/= 23/2013 [ 94.804247] Call Trace: [ 94.804251] ? dump_stack+0x5c/0x7c [ 94.804253] ? __warn+0xc4/0xe0 [ 94.804255] ? warn_slowpath_fmt+0x4f/0x60 [ 94.804256] ? set_next_entity+0x81c/0x910 [ 94.804258] ? pick_next_task_fair+0x20a/0xa20 [ 94.804259] ? sched_cpu_starting+0x50/0x50 [ 94.804260] ? sched_cpu_dying+0x237/0x280 [ 94.804261] ? sched_cpu_starting+0x50/0x50 [ 94.804262] ? cpuhp_invoke_callback+0x83/0x3e0 [ 94.804263] ? take_cpu_down+0x56/0x90 [ 94.804266] ? multi_cpu_stop+0xa9/0xd0 [ 94.804267] ? cpu_stop_queue_work+0xb0/0xb0 [ 94.804268] ? cpu_stopper_thread+0x81/0x110 [ 94.804270] ? smpboot_thread_fn+0xfe/0x150 [ 94.804272] ? kthread+0xf4/0x130 [ 94.804273] ? sort_range+0x20/0x20 [ 94.804274] ? kthread_park+0x80/0x80 [ 94.804276] ? ret_from_fork+0x26/0x40 [ 94.804277] ---[ end trace b0a9e4aa1fb229bb ]---